1. Field of the Invention
This invention is directed at high rate multiplexing circuits, in general, and to a dual channel, high rate multiplexer circuit system, in particular.
2. Prior Art
In the prior art, there are numerous circuits and systems having the general purpose of providing what is known as a data link. A data link is used to, inter alia, communicate from the ground to an airborne craft or vice versa; or from an aircraft to any kind of a vehicle such as another aircraft or even a satellite. The performance of this operation requires the production of a single output signal in order to carry the necessary information. That signal must carry all of the information that is to be communicated whether it is voice generated, sensor generated, or generated from users that are doing specified things, such as reporting the weather, or the like. Whatever that information is, it has to be concentrated into one data stream in order to be used properly and efficiently. This is usually carried out by a multiplexer circuit which takes a number of these signals, from a plurality of users, and concentrates the signals into one output stream which is then transmitted to or from an aircraft as the data link information that it carries.
The multiplexers known in the past have been cumbersome, complex, difficult to produce, heavy, expensive, and so forth. All of these characteristics are undesirable in an aircraft.
In the recent past, a high rate multiplexer capable of operating at frequencies in the hundreds of megahertz region has been developed to take data from users at a synchronized rate and time division multiplex (TDM) the information up to a high rate. This was accomplished with a hybrid circuit approach which took a number of integrated circuits placed onto substrates and mounted into hybrid circuits. Typically, four or more of these hybrid circuits (depending upon configuration) are necessary in order to produce one of the multiplexing circuits.
However, the prior art multiplexers do not operate at a sufficiently high data rate to interact with sensors in order to get pictels, radar sensor information, or other types of information with a large amount of data that has to be transmitted rapidly. For example, in sending a single television frame, the signal is divided into pictels and a very high data rate is required to send a high resolution picture from an aircraft to the ground, or the like. Therefore, to produce a more efficient system, a very fast data rate is required.